JPS61135550A - Control of viscosity of protein hydrolysate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

BACKGROUND OF THE INVENTION TECHNICAL FIELD The present invention relates to the field of protein water decomposition products. In particular, it relates to a method of increasing the viscosity of protein hydrolysates by adjusting their magnesium and calcium contents.

Related Art Protein hydrolysates and methods for their production are well known. Protein hydrolysates are commonly used as flavor enhancers in the food industry and are the source of "meat-like flavours". Furthermore, they are used for nutritional purposes such as protein supplementation, as a source of amino acids for infant formulas, in special dietary formulations, and for the parenteral administration of amino acids.

Protein hydrolysates have also been found to be useful in cosmetic and health care products.

Generally, protein tiger hydrolyzate is produced by chemical or enzymatic hydrolysis of a protein source, and aminoprose is produced by forming a mixture of amino acids and pezotides.

Chemical water splitting involves treating the yew/baigen with acid or alkali. The m,i water layer of the protein source produces amino acids in the physiologically acceptable "L-" form, whereas alkaline hydrolysis produces the less desirable "D" form of amino acids.
−” form, which is rarely metabolized by the human body.

Protein sources are readily available from a variety of sources including animal and/or vegetable proteins. Animal protein hydrolysates can be obtained essentially from any meat source such as beef, pork, lamb, poultry, fish, etc. These may be of milk origin, such as casein, lactalbumin, etc. Plant protein hydrolysates are obtained, for example, from wheat germ, rice bran, corn gluten, soybean protein, flaxseed protein, peanut press cake, yeast, and the like. The protein content of each of these starting materials varies from about 20 to 90% by weight.

In a typical acid hydrolysis method, for example, a protein source is brought into contact with hydrochloric acid to form a hydrolyzed group of proteins.

After the decomposition is substantially complete, the aqueous slurry medium is neutralized with an alkali such as caustic soda to stop the hydrolysis reaction, treated with activated carbon, and filtered through arrows to remove insoluble proteins and substances formed during the reaction. removes amines (non-degradable, insoluble materials such as fibers). The resulting aqueous solution (formed as a result of chemical or enzymatic hydrolysis) is then evaporated to produce a commercially available vine product of the 6-glaze type: liquid containing liquid,
(3) a substantially dry powder; or (3) a substantially dry powder.

However, the main problem that arises when using protein water decomposition products is that they generally exhibit an increase in viscosity over time due to storage. This is particularly true in the case of commercially available hydrolysates with a high solids content, such as vine pastes. The viscosity of the paste reaches such a high level that it actually becomes rock-homogeneous after long-term storage. This makes it difficult to remove the paste from the holding container even after heating. The removed paste is difficult to disperse and solubilize at the same time.

SUMMARY OF THE INVENTION Applicant has discovered a method for treating protein hydrolysates that controls their viscosity and thereby substantially avoids all of the above problems.

In particular, it has been found that the cause of the increase in viscosity over time is the presence of magnesium ions and, to a lesser extent, calcium ions contained in the protein hydrolyzate. It was found that this can be controlled by adjusting the content.

A decrease in these ions immediately results in a decrease in viscosity, and upon storage the hydrolyzate becomes resistant to viscosity increase. Conversely, an increase in these ions in the hydrolyzate immediately increases the viscosity, which further increases upon storage.

In the context of the present invention, "protein hydrolyzate" refers to protein hydrolyzate at any stage of manufacture, such as a neutralized or inactivated reaction product, either by chemical or enzymatic hydrolysis, and unfiltered. , products that are in slurry form, products that are filtered with the same reaction product and are in solution form, regardless of the solids content (liquid or paste)... . Furthermore, the term "protein hydrolyzate" also includes embodiments in which it is one or more protein hydrolysates derived from each mutagenic protein source and/or each at hydrolysis reaction.

In particular, the viscosity of protein hydrolysates is determined by complexing the magnesium and calcium ions contained therein with soluble physiologically acceptable pyrophosphates and thereby removing the insoluble magnesium and calcium salts formed. It turns out that it can be reduced.

It is completely unexpected and surprising that the addition of pyrophosphate to a protein hydrolyzate causes a temporary viscosity decrease. Salts, especially disodium orthophosphate, are added to act as stabilizers and/or buffers. However, the presence of disodium orthophosphate was found to increase the viscosity of the treated protein hydrolyzate over time. By using essentially the same compound, i.e., pyrophosphate in place of orthophosphate, the pyrophosphate actually reduces the viscosity to the desired extent, while at the same time... Provided that it is added...
...was found to provide a stabilizing effect similar to disodium orthophosphate.

Furthermore, the use of pyrophosphates confers additional benefits: it does not affect the sensory profile of the treated hydrolyzate, it does not affect the hygroscopicity of the treated hydrolyzate, it does not affect the amino acid composition of the hydrolyzate. It does not have the usual phosphate aftertaste which is observed in practice with disodium orthophosphate treated hydrolysates which produce no effect.

Additionally, the present invention has made it possible to use raw materials with low protein content as protein sources for the hydrolyzate. These low protein content feedstocks were found to have correspondingly high magnesium contents which caused the viscosity problems mentioned above. However, in accordance with the present invention, these viscosity problems have been eliminated by using pyrophosphate to complex and precipitate magnesium and/or calcium ions.

In another aspect of the invention, if an increase in the viscosity of the protein hydrolyzate is desired, the magnesium ion content and optionally the calcium ion content of the hydrolyzate may be increased by reducing the protein coolant with a high magnesium (or calcium) content. Use or
Or it can be increased by adding soluble magnesium and/or calcium salts to the hydrolyzate.

DETAILED DESCRIPTION OF THE INVENTION Without being bound by theory, it is believed that the mechanism of increase in viscosity over time of the hydrolyzate is due to magnesium ions, to some extent calcium ions, and amino acids (approximately 5
It is believed that this is based on the interaction with the carphocycl group of 0311t%), the organic acid contained therein (approximately 71% by weight), and the phosphate (approximately 2%) also contained in the hydrolyzate. The resulting interaction products have low bath solubility and form a highly viscous medium over time.

Similarly, when disodium orthophosphate is used to act as a stabilizer/buffer in a protein hydrolyzate, magnesium Some complexation with/or calcium ions may occur; however, such complexation is believed to be negligible because only one bond is available to react with magnesium and calcium. ing.

Most of the added orthophosphate salt therefore remains in the protein hydrolyzate solution, where it apparently interacts with the remaining components and causes an increase in viscosity over time.

In contrast, the pyrophosphate used in the present invention has at least 6 reactive sites for conjugation with magnesium or calcium. For this reason, the differences between the release and bath solubility constants of pyrophosphates compared to orthophosphates make pyrophosphates highly potent even when only small amounts of magnesium or calcium ions are present. It can provide complexing and precipitation capabilities.

Pyrophosphate salts that can be used in the present invention include all edible and bathable salts such as tetrasodium pyrophosphate, tetrapotassium pyrophosphate, ammonium pyrophosphate, sodium acid pyrophosphate, potassium acid pyrophosphate, and ammonium acid pyrophosphate. include.

Any one or more of these pyrophosphates can be used simultaneously.

Although picrates are characterized herein as complexing and precipitating elements of magnesium and/or calcium ions in proteinaceous hydrolysates, it is noted that the present invention is not limited solely to the use of pyrophosphates. Should. Although pyrophosphate is clearly preferred as it has been found to be physiologically acceptable in food products and is capable of forming insoluble magnesium or calcium precipitates, other precipitants may also be used. can. These other precipitants provide anions that can complex with the magnesium and/or calcium ions in the protein hydrolyzate and form a precipitate. Preferably, these agents are physiologically acceptable.

Such precipitating agents include physiologically acceptable alkali metal and ammonium salts, such as carbonic salts, silicates, and the like. As in the case of pyrophosphates, these precipitants are used alone or in any combination with each other.

However, when using precipitants other than pyrophosphates, protein hydrolysates should be adjusted to alkaline conditions as these precipitants are generally only effective above 7.0 must be noticed. In this alkaline state, the magnesium and/or calcium salts of each precipitant are insoluble and precipitate out of the hydrolyzate solution for removal. In fact, even orthophosphates can be used as precipitants, provided that the hydrolyzate is alkaline. After removal of the precipitate, the protein hydrolyzate is acidified back to the customary range of 4.5 to 6.0.

Due to the decrease in viscosity, pyrophosphate is added after the initial hydrolysis step, i.e. after the I5A family protein has come into contact with an enemy, an alkali or an enzyme and the acid or alkali has been neutralized or the enzyme has been inactivated. It is added to the protein raw water decomposition product at any time. After this neutralization or inactivation step, the pyrophosphate is added aO in any next step of protein 710 hydrolyzate production. Alternatively, the pyrophosphate may be added to the final 7JO water splitting product.

Similarly, the other precipitants mentioned above are
is added to the protein hydrolyzate in any subsequent step after the neutralization or inactivation step provided that the alkaline conditions are adjusted. Since one of the main objectives of the present invention is to prevent the viscosity of the final hydrolyzate from increasing over time, it is also preferred that the pyrophosphate be added during the preparation of the hydrolyzate rather than afterwards.

It is therefore desirable to add the pyrophosphate during preparation of the hydrolyzate prior to grading, since addition of pyrophosphate can form magnesium and/or calcium precipitates that must be removed. In this way, magnesium and/or calcium precipitates are removed simultaneously with humins and other unresolved substances. The remaining manufacturing steps are then carried out in a conventional manner, including evaporation of the protein hydrolyzate to any desired extent.

The pyrophosphate is first dissolved in an aqueous solution and then added to the protein hydrolyzate or added as a dry powder. The former is preferred as it seems to allow better dissolution of the pyrophosphate, thereby increasing its combined effect with magnesium and calcium ions.

In another embodiment, the pyrophosphate is added to the finished protein hydrolyzate solution. The treated solution is further treated to remove the magnesium and/or calcium precipitate that forms. Such precipitate removal may be accomplished by any conventional method including filtration, centrifugation, and the like. Of course, if a hydrolyzate paste is to be processed, it is advantageous to first dilute the paste to a more workable composition by adding an aqueous medium before adding the pyrophosphate. If the pyrophosphate is applied in solution form rather than in powder form, such addition generally satisfies both the dilution and processing of the paste at the same time. The solution containing the pyrophosphate in the arrow is thoroughly mixed and the resulting precipitate is removed in the manner described above. If desired, the added water is then removed from the solution to re-form the paste.

Regarding this alternative embodiment, once the protein hydrolyzate solution is stored and the viscosity begins to increase, the addition of pyrophosphate does not reduce the existing viscosity. Rather, magnesium and/or
Alternatively, it merely reacts with calcium ions and does not so far interact with the various components of the protein hydrolyzate to prevent a substantial increase in viscosity over time.

Of course, the actual amount of pyrophosphate (or other precipitant) added to the protein hydrolyzate will depend on the amount of magne7 contained in the hydrolyzate.
depending on the amount of umium and/or calcium ions and the desired viscosity reduction over time.

Ideally, in order to reduce viscosity increase over time as much as possible, the pyrophosphate additive should now react with all the magnesium and calcium ions and complex these contained in the protein hydrolyzate. is the stoichiometric amount equal to the amount of ions. For example, considering the addition of tetrasodium pyrophosphate, the resulting chemical reaction can be expressed as follows: Na4P2O7+ 2Mg" 2gMg 2p 2
o, + 4Na”↓ or in other words, 1 mole of pyrophosphate removes 2 moles of magnesium ions (or 2 moles of calcium ions). One skilled in the art can easily calculate the amount of pyrophosphate needed to react with these ions, knowing the amount of ions (and can easily measure them), but equilibrium and dissociation considerations will limit the chemical amount used. Even in greater than stoichiometric amounts, all of the magnesium and calcium ions do not react.Therefore, a small amount of magnesium and calcium ions remain in the protein hydrolyzate, resulting in a slight increase in viscosity during storage.

The recommended loading of pyrophosphate for a conventional protein hydrolyzate is approximately 45% solids hydrolyzed vegetable protein (from corn, rice, and wheat protein sources) containing approximately 2540 ppm magnesium on a dry weight basis. ffs addition of about 0.5% by weight of tetrasodium pyrophosphate to the neutralized slurry is sufficient to reduce the magnesium content to about 1490 ppm on a dry weight basis, and the hydrolyzate paste made from this neutralized slurry Its viscosity is equivalent to molasses at room temperature, with a very acceptable consistency and consistency when stored.

If an excess of pyrophosphate, ie more than the stoichiometric amount, is added, this excess is likely to act as a stabilizer and/or buffer in the same manner as the commonly used orthophosphate.

Regarding the relationship between viscosity and pyrophosphate addition) x JJ1, the relationship between viscosity and pyrophosphate addition is It is impossible to describe effectively. However, for a paste hydrolyzate containing about 75-85% solids by weight, after storage for at least about 3 months, it is necessary to avoid rock-solid conditions and obtain a paste with the same viscosity as molasses at room temperature. The magnesium ion concentration of about 15LI (dry weight basis)
] ~2000 ppm.

Another aspect of the invention in which it is desirable to increase the viscosity of the protein hydrolyzate is to increase the magnesium ion content (and optionally the calcium ion content). This is done by adding a source of magnesium and/or calcium ions.

The viscosity increases over time by adding soluble magnesium and/or calcium (preferably edible salt) to the water decomposition product. These salts include magnesium and/or calcium chlorides, F7It salts, phosphates, carbonates, hydroxides, and the like.

Combinations of these salts can also be used.

Alternatively, the source of magnesium and/or calcium ions may be derived from a starting material having a high content of magnesium and calcium ions. As is evident from 91 below, which shows the chemical composition of a number of protein raw materials, materials such as wheat germ, rice bran, etc. have relatively high contents of magnesium;
Therefore, it serves as a source of magnesium ions to increase the viscosity of protein hydrolysates.

As with the addition of monolophosphate to reduce viscosity, the required addition of magnesium and/or calcium ions to increase viscosity can be more specific due to the large number of variables on which viscosity depends. It cannot be stated. However, it is well within the skill of those skilled in the art to determine the particular amount of magnesium added to a particular protein hydrolyzate to obtain the desired viscosity increase for a given application.

It has been found that significant viscosity effects are typically obtained when the total solids content of the protein hydrolyzate is high, generally higher than 70i1%. However, the viscosity is not as good and the solid content is about 453! Even when Ui% is as low as that, it is still significant. 4
Below 5% by weight, the hydrolyzate is so dilute that no reduction in viscosity over time due to the addition of magnesium or calcium precipitants is generally measurable. Of course, the addition of significant amounts of magnesium or calcium ions even to a 45eII# solution significantly and markedly increases its viscosity.

Having described the basic concept of the invention, the following section provides a more detailed example. For example, Chubu and 俤 are based on weight. Additionally, the viscosity measurements shown in the examples were made using a Brookfield Synchro-Leftric Viscometer Model LVT using a Sgindle TE at 5 rpm at a temperature of 65°C. However, these examples should in no way be construed as limiting the invention.

Example 1 This example has higher magnesium than the low magnesium control sample! It is demonstrated that the use of a protein source material containing an amount of 7 cum increases the viscosity of the hydrolyzate over time, and the rate of viscosity increase over time is significantly enhanced.

3.182II corn gluten (sample 1) is 3.35
9, acidify the protein with 32 g of concentrated hydrochloric acid and 2,000 g of water at a temperature of 125 to 160 °C.
Stir for an hour to split rRm water. The resulting mixture is 1,18
Add 2 g of soda carbonate and 73211 50% caustic soda to neutralize to 5.3 -.

This neutralized slurry is filtered and treated with activated carbon. The filtrate is evaporated to form a "paste" having a solids content of approximately 85% by weight.

In addition, 66N corn gluten and 67N weight
3,182 g of a protein source raw material mixture consisting of wheat germ flour (Sample 2) or 50% corn gluten, 25% by weight wheat germ and 25% rice bran (Sample 3) was prepared in the same manner as above. Process.

The magnesium and calcium contents of protein hydrolysates and their viscosities at each stage of storage are shown in Table H: The above data indicate that the use of materials containing high amounts of magnesium increases the viscosity of protein hydrolysates over time. It is demonstrated that the rate of increase in viscosity over time can be significantly increased. Samples containing wheat germ (stock 2) or both wheat germ and rice bran (sample 6) - these were compared to the control corn gluten (sample 1).

Both have high magnesium content - have a significantly higher viscosity on storage than the control corn gluten samples.

Example 2 This example demonstrates the effect of reducing viscosity when storing a protein hydrolyzate and adding pyrophosphate thereto in doses according to the invention.

A raw protein mixture of 3,1829 consisting of 10% by weight of wheat germ, 60% by weight of corn gluten and 60% by weight of rice bran was mixed with 3,359.9% of 32% concentrated hydrochloric acid and 2% by weight of concentrated hydrochloric acid.
,000 g of water was added to the protein mixture and 125-1
Hydrolysis is carried out by stirring for 4 hours at a temperature of 30°C. The resulting mixture is 1,182. @ carbonated soda and 732g of 50
Neutralize to -5°3 by adding % caustic soda. This neutralized slurry is divided into a series of samples to which each dose of tetratetrasodic pyrophosphate is added. Each sample is filtered and treated with activated carbon.

The sample is evaporated to form a paste having a solids content of approximately 851 i. Table 1 has attached 7JoV! Data regarding lophosphate content, magnesium and calcium content after filtration and respective viscosity of each sample due to storage are shown.

Table 1 Amount of added pyrophosphate M after final filtration Gnesium content after final filtration (for treated sample)
Calcium content 0 2.214
429U・2 1.7
86 3260・4
1.345 2740.6
1, tlUo 2260.
8 726 206
1.0 512 1
901.2 345
1671.4 219
1551.6 131
150 paste viscosity tJ, 1 1.7 3.3 5.0 6.6
U, 11°0 1.8 2.5 3. IJOll
11.3 0.5 11.7 0.90
,I O,20,3Ll,3 0.5L],U
7 U. 1 0.2 0.2 0.3L],
07 0. I Ll, I Ll, I
Ll, 10, tJ5 0. U8 0. I O,
10,1υ, LlI U, U5 0.1 0.
I Ll, IO, 010, 050, 10, 10,
1 The above data show that the addition of monorophosphate according to the invention not only immediately reduces the paste viscosity of the protein hydrolyzate, but also, most importantly, allows the hydrolyzate to be stored in a manner that resists viscosity increase. Controls the viscosity of medium hydrolyzate
demonstrate that

Example 6 In this example, an amount of potassium pyrophosphate of approximately 0.4 wt M% is added to one of the samples from Example 2. The sample is filtered, treated with activated carbon, and then evaporated to form a paste with a solids content of approximately 8531 L volumes. The magnesium content after filtration is about 1650 ppm on a dry basis. After 8 months of storage, the paste viscosity is approximately 1, Ox I measured at 65°C.
Ll' cps, which is an acceptable viscosity equivalent to molasses.

Example 4 This example demonstrates the effect of pyrophosphate treatment on viscosity when increasing the total solids content of the protein hydrolyzate. 0.
An 8% by weight sodium pyrophosphate solution is added to Protein 7110 hydrolyzate solutions containing various total solids concentrations. The results are shown in Shishi■.

The data in Table 1 demonstrate that the effect of -2 lophosphate on viscosity is greater at high solids contents, especially total solids above 70 modulus.

Example 5 A panel of 24 expert tasters (triangular tasting test and selective tasting test) prepared in Example 2 prepared in Example 2 with samples containing 0.45% added pyrophosphate sodium and a control sample of the neutralized slurry. The differences, if any, between treated and untreated protein water digests were determined.

The results of this test show that the organoleptic profile of the treated 710 hydrolyzate is unchanged. There is no significant change in either taste or quality of the pyrophosphate tetrasalt treated protein hydrolyzate compared to the untreated hydrolyzate.

Example 6 This example shows that the addition of pyrophosphate to a protein hydrolyzate does not result in a significant change in its amino acid composition.

Samples of the treated and untreated protein hydrolysates used in Example 5 are each analyzed to determine their amino acid composition. The results of this analysis are shown in Table V: Table V Threonine 0.95
0.96 serine 1.57
1.63 glutamic acid 9,
82 9.83 Proline
2.95 2.89 Glycine
0.97 0.88 Alanino
2,95 2.80 Valine 1.20 1.76 Methionine 0.47 0
．． 3-physoleucine 0.56
0.520 Ishin
1.52 1.49 Tyrosine
0.25 0.19 Phenylalanine
1.22 1.15 Histidine 0.48 0.53 Lysine 0.66 0
．． 85 Ammonia 0.50
0.54 Arginine 1
．． 41 1.10 total
29.70 29.72 Example 7 This example shows that the addition of pyrophosphate does not significantly affect the hygroscopicity of the treated protein hydrolyzate.

Again, samples of the treated and untreated protein hydrolysates of Example 5 are exposed to various degrees of relative humidity at a constant temperature of 25° C. after first removing all moisture from each sample to form an anhydrous material. The results of this wiping test are shown in Table 1 and show that the hygroscopic properties of this garment are not affected by the pyrophosphate treatment.

Relative humidity % Untreated Treated 12% 2.0 2.066
6. B 7.048%
Unconfirmed 14.076chi
27.0 Unconfirmed 97% 65.
5 50.2 Example 8 This example demonstrates how the viscosity of a protein hydrolyzate is increased by adding soluble magnesium or calcium salts. A hydrolyzed protein derived from corn gluten containing 240 ppm magnesium and 80 ppm calciramula on a dry weight basis is divided into two samples. Add each deposit of magnesium chloride to one sample. Each weight of calcium chloride is added to the other sample. 1
The effect on paste viscosity after storage is shown in Table 3.

It can be seen that adding magnesium or calcium to a protein hydrolyzate increases its paste viscosity. However, the addition of magnesium has a very large effect on viscosity.

Example 9 This example demonstrates the effect of pyrophosphate treatment on paste viscosity of enzymatically hydrolyzed protein hydrolyzate (1!1# mustard oil).

Fermented ginger oil (30% solids) (Kikkoman International Inc., Francisco,
Potash 7 Ornia) EMt - Heat to 60°G, add pyrophosphoric acid amount of soda to each pile, hold at 60°C for 1 hour,
The filtrate is concentrated to a paste having about 851 g solids by filtration to remove the pyrroline compacted magnesium and calcium precipitate. Table 1 shows data on the amount of pyrophosphate added, the magnesium and calcium content after filtration and the respective viscosity of each paste due to environmental storage.

Table■ Addition amount of tetrahydrous sodium pyrophosphate Magnesium gold member 3 after auditory canal 2.210
0.4 1,2730.8
5931.2
308 Paste Viscosity (x10' cps, 65°C) Calcium Content After Filtration (Storage Months) 1.9
11 U, ILl 1.81.1
38 0°10 0.80835
0.12 0.35407
0.12 0.22 The above data demonstrate that adding pyrophosphate to an enzymatically hydrolyzed m-protein hydrolyzate decreases the paste viscosity of the hydrolyzate after storage for at least two months.

Example 10 This example demonstrates the use of precipitants other than pyrophosphate, such as orthophosphate, as well as the use of magnesium and/or
or demonstrate that the calcium content can be reduced by 1tt- thereby reducing the paste viscosity of the hydrolyzate, i,ooo,! A neutralized protein hydrolyzate slurry sample of i+ is obtained according to Example 2. The pt-t of the sample is adjusted to a value of 8.0 by adding organic soda. Add 5.0y of disodium phosphate powder to the slurry to precipitate the insoluble magnesium and calcium orthophosphates.

After filtration of the precipitate, the filtrate is acidified to 'C5,3-- by adding hydrochloric acid. Next, the liquid protein hydrolyzate is evaporated and 8.5
A paste is formed with a solids content of m11%. Table■
shows data on magnesium and calcium content of the Tonichi hydrolyzate before and after orthophosphate treatment.

Table ■ Unprocessed 1.995 29
5 Orthophosphate treatment 19 5
8 The above data demonstrate that treatment of protein hydrolyzate with alkaline disodium orthophosphate reduces the magnesium and calcium content, thereby also reducing the paste viscosity of the hydrolyzate upon storage.

Claims (14)

[Claims] (1) A method for controlling the viscosity of a protein hydrolyzate, which comprises adjusting the magnesium content of the protein hydrolyzate. (2) Adjusting the calcium content of the protein hydrolyzate,
A method according to claim 1. (3) The method according to claim 1, wherein the viscosity of the protein hydrolyzate is reduced by reducing the magnesium content. (4) The method according to claim 2, wherein the viscosity of the protein hydrolyzate is reduced by reducing the calcium content. (5) The method according to claim 1, wherein the viscosity is increased by increasing the magnesium content of the protein hydrolyzate. (6) The method according to claim 2, wherein the viscosity is increased by increasing the calcium content of the protein hydrolyzate. (7) In the method for reducing the viscosity of protein hydrolyzate, (a
) adding pyrophosphate to the hydrolyzate to form insoluble magnesium and/or calcium pyrophosphate salts;
and (b) the above method, characterized in that the insoluble salt is removed. (8) The method according to claim 7, wherein the pyrophosphate is an alkali metal pyrophosphate or ammonium pyrophosphate. (9) The method according to claim 7, wherein the pyrophosphate is tetrasodium pyrophosphate, tetrapotassium pyrophosphate, or tetraammonium pyrophosphate. (10) The method according to claim 7, wherein the protein hydrolyzate is a plant or animal protein hydrolyzate obtained by acid, alkaline or enzymatic hydrolysis, or any combination thereof. (11) In the method for reducing the viscosity of protein hydrolyzate, (
a) adjusting the pH of the protein hydrolyzate to above 7.0; and (b) adding a salt selected from the group consisting of carbonates, silicates, orthophosphates or a combination thereof to dissolve insoluble magnesium and/or or forming a calcium salt, and (c) removing the insoluble salt. (12) A method for increasing the viscosity of a protein hydrolyzate, which includes adding a source of magnesium and/or calcium to the hydrolyzate. (13) The method according to claim 12, wherein the magnesium and/or calcium source is a soluble salt of magnesium and/or calcium. (14) The method according to claim 12, wherein the source of magnesium and/or calcium is a protein material having a high content of magnesium and/or calcium.